RC circuit with dc current source

  • Engineering
  • Thread starter Melizard0
  • Start date
  • #1
Melizard0
2
0

Homework Statement


Solve for the current in each branch of the following circuit as a function of time & derive and expression for the time dependence of teh emf of the constant current source in the circuit below.


Homework Equations



Zc = Xc = 1/(wC) = t/(2pi*C)


The Attempt at a Solution



I attempted to use the mesh method:

Loop 1:
-1000(i1)+50-(Zc)(i1)+(Zc)(i2)=0

Loop 2
-(Zc)(i2)+(Zc)(i1)-3500(i2)+3500(i3)=0

Loop3:
-3500(i3)+3500(i2)-5000(i3)-V=0

This quickly got confusing when I substituted Zc for t/(2pi*120mF).
I have no idea how to solve this problem when it has both a capacitor and a current source.

I also do not understand what the second part of the question is asking.

I would appreciate any help/insight that you could offer. Thanks.
 

Attachments

  • electronics.jpg
    electronics.jpg
    19.6 KB · Views: 556

Answers and Replies

  • #2
Kruum
220
0
We can't see your picture until it's been approved, but I can tell you that for these kind of questions, usually, you have to either use differential equations or Laplace transformations. I assume you're familiar with one of them?

The second part gets me too. I can understand each word separately, but put them together and it's jibberish to me. :blushing:
 
  • #3
Redbelly98
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
12,143
165
The 2nd part asks for the voltage across the current source, as a function of time.

As a start, you could get the steady-state currents and voltages (t→∞).

To solve this, I think we need some initial condition that isn't given. For example, perhaps the capacitor voltage is zero at t=0?
 
  • #4
Melizard0
2
0
That's all the information that I'm given. I have a feeling that since the current varies with time that I have to treat it like an ac circuit, and put in a function instead of i. I'm meeting with my prof today, so hopefully he provides some more insight.
 

Suggested for: RC circuit with dc current source

  • Last Post
Replies
16
Views
492
Replies
7
Views
906
Replies
3
Views
1K
  • Last Post
Replies
7
Views
677
Replies
6
Views
767
Replies
5
Views
564
  • Last Post
Replies
4
Views
442
  • Last Post
Replies
12
Views
405
Replies
5
Views
582
Top